Why the Bridge Is There
The SimtoLink BACnet MS/TP to IP gateway puts MS/TP DDCs, sensors, and actuators on an RS-485 bus into a BACnet/IP domain without rewriting their objects. It is the usual answer when a retrofit has old and new controllers together, needs routing across VLANs, and has to isolate BBMD broadcasts, while object instances and property meaning stay the same.
Routing tables, COV subscriptions, segmentation, and a network-number planner are included. It works with a central workstation, an energy-management system, and an MQTT bridge going north. SimtoLink imports EDE files, gives a checklist for reading a Wireshark capture, and advises how to split the site into segments, so the low-voltage integrator spends less time on joint commissioning and acceptance.
Reliability on Site
CE and FCC coverage is part of the electrical-safety and EMC file. Each port has surge protection and rejects a reversed supply. Ground is reinforced and the layout is split into zones, which holds down ground loops and common-mode noise. Outdoor and coastal versions can step up the ingress rating and add a corrosion-resistant coating.
A batch import covers the parameters. Threshold rules, event video, and waveform capture depend on the model. Configuration and firmware both travel by OTA. On site, run a power-on self-test, sync time on the link, and spot-check a sample of readings. If the point is for metering or for safety, SimtoLink helps send the unit to a third-party metrology institute and supplies the type-test documents.
Key Hardware Parameters
The table is the typical build, for selection and for the technical clauses in a bid. Ask SimtoLink for the Hardware Specification and the Installation and Commissioning Guide if you need a wider range, redundant power, or an intrinsically safe variant. Order codes in the family can differ a little. Follow the nameplate and the documents shipped with the gateway.
| Parameter | Specification | Notes |
|---|---|---|
| CPU | x86 quad-core | Fanless |
| Memory / storage | 8G/64G SSD | Industrial grade |
| Ethernet | 2×GbE | RSTP redundancy |
| Serial | 4×RS232/485, configurable | Isolation 2.5kV |
| Wireless | LoRa+4G | External antenna |
| Protocol stack | Modbus/OPC UA/MQTT | Expandable |
| Operating temperature | -22～61 ℃ | Wide temperature |
| Power supply | DC 12～48V | Redundant terminals |
| Installation | Wall mount | Grounding required |
| Security | Allow-list ACL | Firmware signature check |
Typical Use Cases
Three retrofit shapes, for choosing the gateway and judging whether the join is worth it:
Keep the DDC and Come Online in Stages
Leave the MS/TP field devices where they are. When an IP head-end or a cloud platform is added, the gateway routes transparently, so you do not rewire the bus or reflash every controller.
Subnets and BBMD
BACnet broadcasts and directed requests move between buildings and between VLANs that a firewall keeps apart. That is the layout a large campus wants: zones managed locally, monitoring in one place.
Chiller Plant and Energy
MS/TP chillers meet the central energy platform on the IP side. The gateway gathers the high-rate points and the alarm links that COP optimization and load forecasting need.
Wiring, Ground, and the Yearly Check
- Read the supply range and the polarity before the gateway is powered. A meter on the bus voltage and the breaker is the check when the panel schedule is old.
- The RS-485 run is shielded twisted pair, grounded at one end, and it stays out of the same long tray as high-power cable.
- On the bench, read and write both ways with the head-end and fire a threshold before the unit is moved to the plant room.
- If it is outdoors, leave drainage and ventilation clear, look at the gasket on a round, and keep lightning earth resistance inside the local limit.
- While it is in service, sample the points and archive logs every 12 months.
Ordering, Documentation, and Support
With the gateway, SimtoLink provides the hardware specification, a dimension drawing, a wiring table, and a sample project. Volume orders can add a sample review and inspection at the factory. Warranty and calibration are whatever the contract and the shipping papers say.